Russian Journal of General Chemistry, Vol. 75, No. 10, 2005, pp. 1674 1675. Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 10, 2005,
pp. 1753 1754.
Original Russian Text Copyright
2005 by Pypowski, Koval’, Erchak.
LETTERS
TO THE EDITOR
A Procedure for Preparing Morpholinomethylhydrosilane
K. Pypowski*, T. A. Koval’**, and N. P. Erchak*
* Universit of Podlasie, Siedlce, Poland
** Pushkin Brest State University, Brest, Belarus
Received February 11, 2005
Morpholinomethylhydrosilane I is used in the syn-
thesis of zwitterionic hypercoordinated organosilicon
compounds with the Si O C and Si S C bonds [1 5].
It is prepared by reduction of morpholinomethyltri-
alkoxysilanes II with lithium aluminum hydride in
diethyl ether.
N
SiH3
LiAlH4, Et2O
N
Si(OR)3
LiOEt, Al(OEt)3
O
O
IIa, IIb
I
R = OMe (a), OEt (b).
Synthesis of I involves separation of the precipitate
by filtration and isolation of the hydrosilane by distil-
lation. The yield of I reaches 61% [5]. One of the
major factors decreasing the yield of I may be its
hydrolytic instability. Indeed, complete hydrolysis of
the Si H bonds of hydrosilane I with water vapor in
the film occurs at room temperature within 5 min.
The hydrolysis product of I, (morpholinomethyl)sil-
sesquioxane III, according to the IR data, contains no
Si H bonds.
(Morpholinomethyl)hydrosilane I. A 2.0-g portion
of LiAlH4 was added over a period of 30 min with
vigorous stirring to a solution of 10.8 g of IIb in
100 ml of anhydrous diethyl ether. The mixture was
gently refluxed for 8 h and allowed to stand for 16 h
at room temperature. The solvent was removed at
atmospheric pressure, after which product I was dis-
1
tilled at 52 C (18 mm Hg); yield 4.8 g (89%). H
NMR spectrum (CDCl3), , ppm (3JHH, Hz): 2.16 q
(2H, SiCH2, 3.6), 2.44 2.48 m (4H, NCH2), 3.58 t
(3H, SiH3, 3.6), 3.68 3.72 m (4H, OCH2) {published
1
data [5]: bp 35 C (11 mm Hg)}. H NMR spectrum
N
SiO1.5
H2O
(C6D6), , ppm (3JHH, Hz): 1.92 q (2H, SiCH2, 3.6),
2.21 2.29 m (4H, NCH2), 3.61 3.67 m (4H, OCH2),
3.71 t (3H, SiH3, 3.6).
I
O
n
III
(Morpholinomethyl)silsesquioxane III. a. Three
drops of I in 0.3 ml of anhydrous diethyl ether were
placed on an aluminum foil to obtain as thin layer as
possible; the layer was kept in air for 5 min. The
resulting colorless amorphous powder was mixed on
the foil surface in an inert atmosphere (Ar) with KBr
and analyzed by IR spectroscopy. The absorption at
The hydrolysis of morpholinomethylhydrosilane in
moist diethyl ether and THF is also very fast.
To exclude the hydrolysis of the Si H bonds, we
improved the step of the isolation of I and performed
its distillation directly from the reaction mixture,
without separating the precipitate. By so doing, the
yield of I was increased to 90%.
1
2300 2000 cm was absent. The absorption of resid-
1
ual OH groups was observed at 3460 cm .
The starting (morpholinomethyl)triethoxysilane IIb
was obtained according to [6].
b. A solution of 0.036 g of water in 5 ml of THF
was added dropwise with stirring to a solution of
1070-3632/05/7510-1674 2005 Pleiades Publishing, Inc.
Pypowski
